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Old 03-17-2014, 01:43 PM
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Default Axle swap in a 78cj5

Hey guys!

I have a 78 cj5, l6, t18 tranny (t18-1b is the stamp). I haven't confirmed the transfer case. AMC 20 rear, dana 30 front.

Backstory

I live in the flat lands of South Dakota, so my main and practically only wheeling is mud and dirt hills, although rocks do tend to stick up in pastures. 90%+ of my rigs time is daily driving. I run 33" tires but 35s or 37s may be in my future depending on how this goes.

I rebuilt my AMC 20 at 16, and well... didn't know enough. It works nicely but because the lash wasn't set correctly my pinion seal leaks. It has solid 1 piece axles (if I remember right I used alloy usa). I also might have a plan for this axle in something else.
The dana 30 front is more or less shelled from when I limped around in 4x4 when the rear had 2 piece axles that failed. At least it will need a new ring/pinion/rebuild kit.

The leaf springs also go under the axles, and the PO used a rancho add a leaf and added...many... leafs. My suspension is practically solid, and to add to that the bottom leaf sticks straight out and they love to carry weeds/bash into rocks.

I'm looking into full length axles. I want this because following another vehicle is pretty hard with the shorter axles as I'm bouncing from wheel trail to wheel trail. This is mostly an issue when going through snow. I also would like to go wider to give me a more stable stance. I currently have 6" fender flairs and I'd like to tuck the wheels between them (73" edge to edge...this would include wheels/tires installed).

My current springs that sit on top of the added leafs are in bad shape (bent, cracked, broken, military wraps coming undone). I don't want to sit up higher than needed to fit the 33/35 inch tires, I also want to go SOA. I'm assuming just about any spring is going to be more comfortable than my current set-up but it would be ideal to get the best ride quality springs.

Getting to it now,

What I want (order of importance):

A more comfortable ride.

SOA and high steer. See "rocks sticking up out of pasture"

Wider axles that when wheels/tires are mounted, measure 73" from the outside of one tire to the outside of the other. I'm sure rim backspacing gives us a little play here. 12.5 or 13.5" wide tires are the most I run.

Stronger axles. I plan on getting lockers front/rear at some point, and the most power I'd give them is a mild 350...but keeping the i6 for now.

What I've researched:
Waggy springs/axles or dana 60s from a rare gem of a ford.

I was pretty set on the dana 60 option but am now leaning towards dana 44s as I don't really beat my axles up rock climbing, and the i6 isn't dumping loads of power. I also read the dana 60s weigh a ton, and the 44s have more ground clearance?

I went to school for mechanical engineering and was a welder for a couple years, as well as hobby welding for most of my life, so I'm not too bad off here. There are loads of junkyards/salvage yards in the area and axles probably won't cost me much due to a low demand.
What's my best option here? Buy a ?year waggy and rob parts?

I appreciate your response!
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Old 03-17-2014, 08:04 PM
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I have wagoneer axles and SOA on mine and it rides good. I bought stock CJ rear springs from JC Whitney. They are military wrapped.
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Old 03-18-2014, 08:17 AM
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Quote:
Originally Posted by WILL View Post
I have wagoneer axles and SOA on mine and it rides good. I bought stock CJ rear springs from JC Whitney. They are military wrapped.
Any lift to the springs or just stock springs? Would you happen to have a picture somewhere? What size tires are you running?

What would you compare the ride to? Mine is so bone crushing hard right now I'll put 5 grand into a softer, smoother ride.
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Old 03-18-2014, 01:07 PM
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Stock CJ springs SOA will give about 6" of lift compared to stock height. That should be plenty for 35s, since 31s fit under my '78 with no lift at all, and I would think also enough for 37s.

At some point though, you have to think about the strength of D44s. As the tires get bigger they apply more leverage on the U-joints and knuckles, and you also need higher (numerically) gears in the diff. 3.36 and the T18A (with 6.32 first) work well with 31s but 35s will probably call for 3.54 or 4.11 and 37s for 4.11 or 4.56 gears. I would say that 37s are about the practical limit for D44s.

A lot of guys just buy an old 1/2 ton or 3/4 ton pickup and use both axles out of it. You also have to consider the wheels, as 3/4 ton trucks have six or eight bolt wheels, and often 16" or bigger rims. If you use the truck rims you may be limited in the tire choices available.

And one other thing - are the body and frame pretty much rust free? You don't want to get too deep into it unless it's a sound vehicle to start with. Body rust is practically impossible to repair, and a frame can get to that point.

What ever you decide, keep us informed on your project. It should be fun.
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Old 03-19-2014, 01:31 PM
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She's pretty rust free, very minor surface rust in a couple small places.

Anyone know of springs low enough to only make the SOA around a 3-4" lift? If I use stock springs and get heavy duty bumpers will that help to lower it any? I really don't want to sit up high and 6" seems too high around 4" is where I'm comfortable, given that I have 2-4" lift right now. Maybe 6" won't be too much when the full length axles are put on. I may end up stretching it as well a little bit.
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Old 03-19-2014, 06:23 PM
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SOA will give you real close to 6" of lift. Using the standard springs instead of the HD military wrap springs will get you a little less, but not much. Full width axles will make it less tippy. This is the kind of project you want to plan very carefully before diving it. You also have to think about countering spring wrap - that can be a big problem with SOA.
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Old 03-19-2014, 11:01 PM
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Quote:
Originally Posted by Ram1500 View Post
Any lift to the springs or just stock springs? Would you happen to have a picture somewhere? What size tires are you running?

What would you compare the ride to? Mine is so bone crushing hard right now I'll put 5 grand into a softer, smoother ride.
They are just stock springs. I have 5.38 gears (I also have a 700r4 so the 5.38s and .7 overdrive combine to make it like having 3.77 gears without overdrive) and either 35" BFG AT's or 34" super swampers. I'm not sure what to compare the ride to. It rides like stock and better than the 4" pro-comp spring under lift I had on it for about 9 years.

I finally found some pictures I posted on here back in 2008 shortly after finishing the spring and axle swap.



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Old 03-20-2014, 09:00 AM
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I like the way that looks Will. Would you happen to have a write-up on how you did that or just a story about it? Looks like I'll be sporting 35"s for sure.
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Old 03-21-2014, 11:47 PM
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The rear axle was very easy. The springs just bolt in place. New perches are set on the top of the axle, then bolting everything together and measuring the pinion angle. Once that is set, the perches are tack welded in place and then everything taken apart to fully weld them in place to the axle.

The front was a little more work. I had a shackle reversal kit already from many years ago. I took the front mount off and welded up new front mounts. The shackle end was already wide enough. I just modified the mount and welded it to the frame at the correct width for the springs. I made new u-bolt plates out of 3/8 or 1/2 inch steel and welded the stock shock mounts to them. The driver's side was like the rear with just welding a new spring perch to the axle. The passenger side had the machined side on the bottom of the axle so I used square u-bolts between the u-bolt plate and a flat plate that extended forward and rearward enough for the u-bolts to go around.

The front spring mount also had to be notched for the steering gear relocation bracket that moved the steering gear forward a little over an inch. In those pictures I was still using the stock drag link but shortly after that changed to a high steer mount on the knuckle for the drag link to connect to.
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Old 03-31-2014, 11:31 PM
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I've made up my mind for now to go with the rock equipment granite kit from ok4wd. Rock Equipment Granite Kit | OK4WD

I'm going with the ARB Suspension (OME) springs which give me around 2-1/2" lift. I also plan on flipping my tie rods to get that clearance I want. From the pictures I've seen it looks like the springs aren't gonna be too bad being under the axle.

This will allow me to get a set of dana 60s and build them up, as well as give me time to plan out my coilover suspension.

Thanks for the input guys! I'll be sure to start my own build thread once I get rolling on this.
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